Why Breaking? Mechanical Braking Types of Mechanical Braking system Disc Brakes Drum Brakes Hydraulic Brakes Electromagnetic Brakes ABS Brakes

1. Breaking
• Why Breaking?
• Mechanical Braking
• Types of Mechanical Braking system
1.Disc Brakes
2.Drum Brakes
3.Hydraulic Brakes
4.Electromagnetic Brakes
5.ABS Brakes

2. Purpose of Breaking
• we can classify the term braking in two parts:
• Mechanical Braking
• Electrical Braking
• In mechanical braking the speed of the machine is reduced solely by
mechanical process but electrical braking is far more interesting than that
because the whole process is depended on the flux and torque directions.
We will further see through the various types of braking but the main idea
behind each type of barking is the reversal of the direction of the flux.
• It is the process of reducing speed of any rotating machine.
• Brakes are used to reduce or cease the speed of motors.

3. TYPES OF Mechanical Braking System
• The different types of braking are
1.Disc Brakes
2.Drum Brakes
3.Hydraulic Brakes
4.Electromagnetic Brakes
5.ABS Brakes

4. Disc Brakes
To stop the wheel, friction material in the form of brake pads (mounted on a
device called a brake caliper) is forced mechanically, hydraulically,
neumatically or electromagnetically against both sides of the disc. Friction
causes the disc and attached wheel to slow or stop.
13

5. Drum Brakes
The drum brake has been more widely used than any other brake design. Braking power is
obtained when the brake shoes are pushed against the inner surface of the drum which rotates
together with the axle. Drum brakes are used mainly for the rear wheels of passenger cars and
trucks while disc brakes are used exclusively for front brakes because of their greater directional
stability.
The backing plate is a pressed steel plate, bolted to the rear axle housing. Since the brake
shoes are fitted to the backing plate, all of the braking force acts on the backing plate. Drum
Brakes are now used mainly for the rear wheels of passenger cars and trucks. When the brake
pedal is depressed while the vehicle is moving backward, the brake shoes expand and contact the
drum.

7. Hydraulic Brakes
The hydraulic brake system used in the automobile is a multiple piston system. A multiple piston system
allows forces to be transmitted to two or more pistons in the manner indicated in Fig. Note that the pressure set up
by the force applied to the input piston (1) is transmitted undiminished to both output pistons (2 and 3), and that
the resultant force on each piston is proportional to its area. The multiplication of forces from the input piston to
each output piston is the same as that explained earlier.
The hydraulic brake system from the master cylinders to the wheel cylinders on most automobiles operates
in a way similar to the system illustrated in Fig.
14

8. Electromagnetic Brakes
Electromechanical braking systems (EMB), also referred to as brake by-wire, replace conventional hydraulic
braking systems with a completely “dry” electrical component system. This occurs by replacing conventional
actuators with electric motor driven units. This move to electronic control eliminates many of the manufacturing,
maintenance, and environmental concerns associated with hydraulic systems.
Electromechanical braking systems (EMB), also called brake by wire, replace conventional hydraulic
braking systems with completely “dry” electrical component systems by replacing conventional actuators with
electric motor driven units. This move to electronic control eliminates many of the manufacturing, maintenance,
and environmental concerns associated with hydraulic systems.
15

9. 16

10. ABS Brakes
Antilock braking system that is between the brake master cylinder and the wheels. The system prevents an
unstable condition of the car under extreme braking conditions. It modulates the pressure of the brake fluid that is
applied to both front brake calipers and/or both rear calipers, preventing the wheels from "LOCKING UP".
Normal brake fluid pressure is restored when there is no longer a possibility of the wheels locking up. Each
wheel has a SENSOR that the system monitors for each wheels rotation. If one of the wheels is turning
slower than the others, the anti lock system releases the pressure to that wheel. The system is designed to
provide positive feedback by way of a kickback on the brake pedal when the system has been activated. The
system works very well in wet or icy conditions, preventing skids and loss of directional control. The ABS
computer controls all functions of the antilock brakes. If there is a problem with the ABS system, the ABS
INDICATOR LIGHT on the dash illuminates. In the event of a failure of the antilock brake system, it does have a
fail safe function that allows for normal braking.